The record and threats of the invasion of palometa Serrasalmus maculatus (Characiformes: Serrasalmidae) in the Patos lagoon drainage, southern Brazil

Abstract

We report the occurrence of an invasive alien species, palometa Serrasalmus maculatus, in the Patos Lagoon drainage. Primary occurrence data were based on three specimens captured and preserved as vouchers in scientific collections. Additionally, we searched for secondary records from unpublished scientific sources, public agencies reports and media news to find additional reports. We discussed the possible pathways of invasion, suggesting as the vector of introduction transpositions from the Uruguay River basin. Ecological implications for ichthyofauna, environmental impacts and risk of other events of invasion in the adjoining basins are discussed.

Non-native freshwater fish from drainages of Rio Grande do Sul State, Brazil

“…In recent years, however, this concern has increased in the scientific community, as shown by published studies on the Pap. Avulsos Zool., 2023;v.63: e202363003 12/17 deleterious effects of exotic species on native fauna (Latini & Petrere-Jr., 2004;Canonico et al, 2005;Pereira & Vitule, 2019) and also by the increase in records of exotic species in the natural environment in Rio Grande do Sul State (Braun et al, 2003;Wincler-Sosinski, 2004;Garcia et al, 2004;Becker et al, 2013;Machado et al, 2015;Fontoura et al, 2016;Bertaco et al, 2016Bertaco et al, , 2022.…”

“…The records of two species that are absent in the official list are further investigated based on recent published reports of occurrence out of their natural geographic distributions (Río La Plata basin, including the Río Uruguay). The palometa, Serrasalmus maculatus Kner, 1858 has been currently recorded in the Rio Jacuí basin, Laguna dos Patos system (UFRGS 28800, Bertaco et al, 2022) (Tables 1 and 2); as well as the piava, Megaleporinus macrocephalus (Garavello & Britski, 1988) recently confirmed in the Laguna dos Patos system (Ramirez et al, 2017) (Table 2). Information about ten exotic species and eight allochthonous species recorded in the main hydrographic basins of the state is presented, based on data from scientific collections and scientific articles.…”

“…More recently, the palometa Serrasalmus maculatus (Serrasalmidae, Fig. 12) has been captured by riverine fishermen in several places in the Rio Jacuí, in the Laguna dos Patos system, and publicized in digital media since the end of 2020 (Bertaco et al, 2022). This species occurs naturally in Rio Amazon and Rio Paraná-Paraguay basins, including Río Uruguay basin (Bertaco et al, 2016;Fricke et al, 2022).…”